add imageName class

Signed-off-by: Tim van Katwijk <[email protected]>

dockerfile_parse/parser.py

@@ -16,7 +16,7 @@
 
 from .constants import DOCKERFILE_FILENAME, COMMENT_INSTRUCTION
 from .util import (b2u, extract_key_values, get_key_val_dictionary,
-                   u2b, Context, WordSplitter)
+                   u2b, Context, WordSplitter, ImageName)
 
 
 logger = logging.getLogger(__name__)
@@ -877,7 +877,9 @@ def image_from(from_value):
         )?
         """)
     match = re.match(regex, from_value)
-    return match.group('image', 'name') if match else (None, None)
+    image = ImageName.parse(match.group('image')) if match else None
+    name = match.group('name') if match else None
+    return image, name
 
 
 def _endline(line):

dockerfile_parse/util.py

@@ -48,7 +48,7 @@ def __init__(self, s, args=None, envs=None):
         :param envs: dict, environment variables to use; if None, do not
             attempt substitution
         """
-        self.stream = StringIO(s)
+        self.stream = StringIO(str(s))
         self.args = args
         self.envs = envs
 
@@ -326,3 +326,121 @@ def get_values(self, context_type):
         if context_type.upper() == "LABEL":
             return self.labels
         raise ValueError("Unexpected context type: " + context_type)
+
+
+class ImageName(object):
+    """Represent an image.
+    Naming Conventions
+    ==================
+    registry.somewhere/namespace/image_name:tag
+    |-----------------|                          registry, reg_uri
+                      |---------|                namespace
+    |--------------------------------------|     repository
+                      |--------------------|     image name
+                                            |--| tag
+                      |------------------------| image
+    |------------------------------------------| image
+    """
+
+    def __init__(self, registry=None, namespace=None, repo=None, tag=None):
+        self.registry = registry
+        self.namespace = namespace
+        self.repo = repo
+        self.tag = tag
+
+    @classmethod
+    def parse(cls, image_name):
+        result = cls()
+
+        if not image_name or str(image_name).isspace():
+            return ImageName()
+
+        if isinstance(image_name, cls):
+            return image_name
+
+        # registry.org/namespace/repo:tag
+        s = image_name.split('/', 2)
+
+        if len(s) == 2:
+            if '.' in s[0] or ':' in s[0]:
+                result.registry = s[0] if s[0] else None
+            else:
+                result.namespace = s[0]
+        elif len(s) == 3:
+            result.registry = s[0] if s[0] else None
+            result.namespace = s[1]
+        result.repo = s[-1]
+
+        for sep in '@:':
+            try:
+                result.repo, result.tag = result.repo.rsplit(sep, 1)
+            except ValueError:
+                continue
+            break
+
+        return result
+
+    def to_str(self, registry=True, tag=True, explicit_tag=False,
+               explicit_namespace=False):
+        if self.repo is None:
+            raise RuntimeError('No image repository specified')
+
+        result = self.get_repo(explicit_namespace)
+
+        if tag and self.tag and ':' in self.tag:
+            result = '{0}@{1}'.format(result, self.tag)
+        elif tag and self.tag:
+            result = '{0}:{1}'.format(result, self.tag)
+        elif tag and explicit_tag:
+            result = '{0}:{1}'.format(result, 'latest')
+
+        if registry and self.registry:
+            result = '{0}/{1}'.format(self.registry, result)
+
+        return result
+
+    def get_repo(self, explicit_namespace=False):
+        result = self.repo
+        if self.namespace:
+            result = '{0}/{1}'.format(self.namespace, result)
+        elif explicit_namespace:
+            result = '{0}/{1}'.format('library', result)
+        return result
+
+    def enclose(self, organization):
+        if self.namespace == organization:
+            return
+
+        repo_parts = [self.repo]
+        if self.namespace:
+            repo_parts.insert(0, self.namespace)
+
+        self.namespace = organization
+        self.repo = '-'.join(repo_parts)
+
+    def __str__(self):
+        return self.to_str(registry=True, tag=True)
+
+    def __repr__(self):
+        return (
+            "ImageName(registry={s.registry!r}, namespace={s.namespace!r},"
+            " repo={s.repo!r}, tag={s.tag!r})"
+        ).format(s=self)
+
+    def __eq__(self, other):
+        if isinstance(other, str):
+            return self.__str__() == other
+        elif isinstance(other, ImageName):
+            return self.__dict__ == other.__dict__
+        else:
+            return NotImplemented
+
+    def __hash__(self):
+        return hash(self.to_str())
+
+    def copy(self):
+        return ImageName(
+            registry=self.registry,
+            namespace=self.namespace,
+            repo=self.repo,
+            tag=self.tag)

tests/test_parser.py

@@ -19,7 +19,7 @@
 from dockerfile_parse import DockerfileParser
 from dockerfile_parse.parser import image_from
 from dockerfile_parse.constants import COMMENT_INSTRUCTION
-from dockerfile_parse.util import b2u, u2b, Context
+from dockerfile_parse.util import b2u, u2b, Context, ImageName
 from tests.fixtures import dfparser, instruction
 
 NON_ASCII = "žluťoučký"
@@ -28,6 +28,116 @@
 instruction = instruction  # pylint: disable=self-assigning-variable
 
 
+@pytest.mark.parametrize(('image_string', 'dictionary'), [
+    (
+            "   ",
+            {"namespace": None, "registry": None, "tag": None, "repo": None},
+    ), (
+            "registry.org/namespace/repo:tag",
+            {"namespace": "namespace", "registry": "registry.org", "tag": "tag", "repo": "repo"},
+    ), (
+            "/namespace/repo:tag",
+            {"namespace": "namespace", "registry": None, "tag": "tag", "repo": "repo"},
+    ), (
+            "registry.org/repo:tag",
+            {"namespace": None, "registry": "registry.org", "tag": "tag", "repo": "repo"},
+    ), (
+            "registry.org/repo",
+            {"namespace": None, "registry": "registry.org", "tag": None, "repo": "repo"},
+    ), (
+            "registry.org/repo@sha256:hash",
+            {"namespace": None, "registry": "registry.org", "tag": "sha256:hash", "repo": "repo"},
+    )
+])
+class TestImageName(object):
+    def test_util_image_name_parse(self, image_string, dictionary):
+        image = ImageName.parse(image_string)
+        assert image.namespace == dictionary["namespace"]
+        assert image.registry == dictionary["registry"]
+        assert image.tag == dictionary["tag"]
+        assert image.repo == dictionary["repo"]
+
+    def test_util_image_name_get_repo(self, image_string, dictionary):
+        image = ImageName.parse(image_string)
+        repo = "/".join(filter(None, (dictionary["namespace"], dictionary["repo"])))
+        assert image.get_repo() == (repo if repo != "" else None)
+        assert image.get_repo(explicit_namespace=True) == "{0}/{1}".format(
+            dictionary["namespace"] if dictionary["namespace"] else "library", dictionary["repo"])
+
+    def test_util_image_name_to_str(self, image_string, dictionary):
+        image = ImageName.parse(image_string)
+        if dictionary["repo"] is None:
+            with pytest.raises(RuntimeError):
+                image.to_str()
+        else:
+            assert image.to_str() == image_string.lstrip('/')
+            assert image.to_str() == (image_string.lstrip('/') if image_string else None)
+            assert image.to_str(explicit_tag=True) == \
+                   image_string.lstrip('/') + (':latest' if dictionary["tag"] is None else "")
+
+    def test_image_name_hash(self, image_string, dictionary):
+        image = ImageName.parse(image_string)
+        if dictionary["repo"] is None:
+            with pytest.raises(RuntimeError):
+                hash(image)
+        else:
+            hash(image)
+
+    def test_image_name_repr(self, image_string, dictionary):
+        # so linter won't trip on unused argument
+        del dictionary
+        image = ImageName.parse(image_string)
+        repr(image)
+
+    def test_image_name_comparison(self, image_string, dictionary):
+        # make sure that "==" is implemented correctly on both Python major releases
+        i1 = ImageName.parse(image_string)
+        i2 = ImageName(registry=dictionary["registry"], namespace=dictionary["namespace"],
+                       repo=dictionary["repo"],
+                       tag=dictionary["tag"])
+        assert i1 == i2
+
+        i2 = ImageName(registry='foo.com', namespace='spam', repo='bar', tag='2')
+        # pylint: disable=unneeded-not
+        assert not i1 == i2
+
+        i1 = ImageName.parse(i2)
+        assert i1 == i2
+
+        i1 = i2.copy()
+        assert i1 == i2
+
+
+@pytest.mark.parametrize(('repo', 'organization', 'enclosed_repo'), (
+        ('fedora', 'spam', 'spam/fedora'),
+        ('spam/fedora', 'spam', 'spam/fedora'),
+        ('spam/fedora', 'maps', 'maps/spam-fedora'),
+))
+@pytest.mark.parametrize('registry', (
+        'example.registry.com',
+        'example.registry.com:8888',
+        None,
+))
+@pytest.mark.parametrize('tag', ('bacon', None))
+def test_image_name_enclose(repo, organization, enclosed_repo, registry, tag):
+    reference = repo
+    if tag:
+        reference = '{}:{}'.format(repo, tag)
+    if registry:
+        reference = '{}/{}'.format(registry, reference)
+
+    image_name = ImageName.parse(reference)
+    assert image_name.get_repo() == repo
+    assert image_name.registry == registry
+    assert image_name.tag == tag
+
+    image_name.enclose(organization)
+    assert image_name.get_repo() == enclosed_repo
+    # Verify that registry and tag are unaffected
+    assert image_name.registry == registry
+    assert image_name.tag == tag
+
+
 class TestDockerfileParser(object):
     def test_all_versions_match(self):
         def read_version(fp, regex):